1. Field of the Invention
The present invention relates to a joint connector, and particularly, to a joint connector that has a small number of parts, has a favorable assembling workability, has a small insertion force when terminals are accommodated within a housing, and a larger holding force for the terminals.
2. Description of the Related Art
<Exclusive Bus Bar>
As joint connectors, for example, joint connectors using exclusive bus bars as shown in FIGS. 10A to 10C are suggested. FIGS. 18A to 18C are conceptual diagrams of joint connectors in which each exclusive bus bar is inserted into a plurality of terminals to perform electrical connection; FIG. 18A shows an example of two terminals, FIG. 18B shows an example of three terminals, and FIG. 18C shows an example of five terminals. In FIGS. 18A to 18C when only terminals a and b among respective terminals a to e of wiring lines 1a to 1e are connected together, an exclusive bus bar 3A shown in FIG. 18A is inserted into the terminals a and b to connect both the terminals together.
Additionally, in a joint connector that connects terminals a to c among the respective terminals a to e of the wiring lines 1a to 1e together, an exclusive bus bar 3B shown in FIG. 18B is inserted into the terminals a to c to connect these terminals together.
Moreover, in a joint connector shown in FIG. 18C, an exclusive bus bar 3C is inserted into the terminals a to e to perform connection when the terminals a to e are connected together.
(Well-Known Example of Joint Connector Including Exclusive Bus Bar)
FIG. 19 is an exploded perspective view of a well-known joint connector (refer to Patent Document 1) using an exclusive bus bar that commonly connects three terminals shown in FIG. 18B. In FIG. 19, a housing 41 of a female connector 40 is a housing of a female connector molded from a synthetic resin material, and a waterproofing seal 44 and a retainer 45 are accommodated inside the housing. Moreover, three terminal accommodating chambers are formed side by side from the retainer 45, and a female terminal fitting 43 to which a covered electric wire 42 is connected is inserted into each terminal accommodating chamber.
A cap 50 is fitted to a front end of the housing 41. The cap 50 is also molded from a synthetic resin material, a cap body 51 has a shape capable of being fitted to the housing 41, and a top face portion of the cap body is formed with an engaging frame 51K capable of entering a lock arm 41K of the housing 41.
An exclusive bus bar 52 shown in FIG. 18B is integrally provided by insert molding within the cap 50. The exclusive bus bar 52 is formed by press-forming a metal plate, and has three male tab portions 52T in one horizontal row capable of being inserted into the terminal fittings 43 within the housing 41. Thus, when the cap body 51 and the housing 41 are brought into a fitting state, the exclusive bus bar 52 is brought into a connection state with the three terminal fittings 43 to electrically connect the respective terminal fittings to each other.
Patent Document 1: JP-A-8-250185
<Problems of Joint Connector of Patent Document 1>
In the joint connector of Patent Document 1, as shown in FIG. 19, the cap body 51, the exclusive bus bar 52, the waterproofing seal 44, and the retainer 45 are indispensable, and there is a problem in that the number of parts increases.
Additionally, the structure of preventing knocking of the tab portions of the bus bar is required when the cap body and the housing fits to each other.
Moreover, in order to increase the holding force of the terminals (that is, to ensure prevention of slip-out of the terminals from the housing), strong engagement is required, and this requires a large insertion force when the terminals are accommodated in the housing.
Additionally, the structure for preventing half-insertion of the terminals is also required.